Ellipsograph.



c. E; BRICKBY.

BLLIPSOGRAPH.

APPLICATION FILED AUG.19, 1908.

Patented May 25, 1909.

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COLLIN I. BRICKEY, OF LA FAYETTE, GEORGIA, ASSIGNOR OF ONE-HALF TO HUGHP. LUMP- KIN, PAUL D. WRIGHT, AND

RALPH A. SNOW, ALL. OF LA FAYEITE, GEORGIA.

ELLIPSOGRAPH.

Specification of Letters Patent.

Patented May'f, 1909.

Application led August 19, 1908. Serial No. 4119,305.

To all whom it may concern.'

Be it known that I, COLLIN P. BRioiinY, citizen of United States,residing at La Fayette, in the county of Valker and State of Georgia,have invented certain new and useful Improvements in Ellipsographs, ofwhich the following is a specification.

My invention relates to an ellipsograph, and the object thereof is toprovide a simple and inexpensive construction which may be readilyyadjusted to describe circles and ellipses of different size. l

In the accompanyingl drawing, illustrating my invention,

i5 specification, wherein like numerals are used to designate like partsthroughout the several figures, Figure 1 is a plan view of my improveddevice. Fig. 2 is a side elevation thereof, and, Fig. 3 is a verticallongitudinal sectional view on an enlarged scalda taken through theoverlapping ends JI the swinging guide arms.

In the practical embodiirlli (ff my mVm" tion, I provide a slide :fate lP1 qvlded Wlth downtumed @Xtewion pieces 2, at its ends, for

mpportngne same in parallel vertically tion to the surface upon which anL ,1,121 me? is to be described. The slide plate 1 is provided in itslength, with a longitudinal slot 3, in which is mounted to slide a guideblock 4, having a vertical shaft 5 projecting therethrough and throughsaid slot 3.

Mounted with their rear downwardly offset ends 6, pivotally secured tothe ends of the plate 1, beyond the ends of the slot 3 thereof, are theguide arms 7 and 8, provided with inner overlapping enlarged ends 9,having longitudinal slots 10 therein, through which slots 10 of saidarms 7 and 8, a bolt 11 extends. The bolt 11 is loosely associatedthrough said slots 10 and is prevented from accidental displacement by anut 12 engaging above a washer 13, resting upon the upper surface of theupper arm 8, which arm is provided with a vertical rib 14, extendinglongitudinally of its enlarged inner end 9, and against which theperipheral edge of said washer slides. rllhe bolt 11 is further providedupon its lower end beneath the arms 7 and 8, with a slotted adjustingblock 15, through which an adjusting bar 16 is slidably mounted, saidadjusting bar 16 being secured at one end to the upper end of thevertical guide block shaft 5, and being adapted to be longitudinallyadjusted through, and to be locked in its adand forming apart of thisjusted position with, the block 15, by a set screw 17 engaging withinsaid block. 'llo the lower end of the guide block shaft 5, is secured asecond adjusting block 18, similar to the slot 15, and through which thepencil bar 19 is longitudinally slidably mounted, a nd adapted to besecured in the desired position by means of a set screw 20, engagingwithin said block 18.

In describing an ellipse, with my improved device, with the same inposition as shown in Fig. 1, the bolt 11 is moved inwardly toward theslide platel, theguide block 1 b eing started upon its` sliding movementin one direction or the other, and the movement continued until the saidbolt is in the Same rela five position upon the opposite side of Saidplate 1, when as will be seen, one-half ai" the desired ellipse willhave been drawn. The movement is then reversed, the guide block 1 beingstarted upon its travel in the same direction as heretofore, and whenthe said bolt 11 has reached its foimer position, as shown in Fig. 1,the desired ellipse is complete. From this, it will be seen that thelength of the pencil bar 19 from the center of the guide block shaft 5,is equal to onehalf of the minor axis of the ellipse drawn,

and that the sum of the lengths of the said pencil bar and the adjustingbar 16, from the center of the bolt 11, inasmuch as the same mustnecessarily be longitudinally alined with one another, equals one-halfof the major axis of said ellipse. From this, it will be readilyunderstood that the bolt 11 must move at exactly right angles to theslot 3 to describe a perfect ellipse, and in order to insure of suchmovement, of said bolt, I provide the enlarged ends 9 of the arms 7 and8, with toothed racks 21, upon relatively opposite longitudinal sides oftheir slots 10, and I further provide the said bolt 11 with a circulartoothed portion 22 to engage the said racks 21, whereby the slidingmovement of said bolt, within said slots 10 of said arms 7 and 8, willbe uniform as the said arms are swung.

From the foregoing, it will be apparent that, by adjusting the length ofthe pencil bar 19, and adjusting bar 16, any desired size and shape ofellipse may be obtained, while by adjusting the said bar 16, until thecenter of bolt 11 is over the center of the guide block shaft 5, a truecircle of a radius equal to the length of the pencil bar 19 from saidcenters,

may be drawn. I therefore provide the adjusting block l5 with its lowerface cut away in order to allow the same to be moved over the upper endof said guide block shaft 5.

A U-shaped rod frame 2B, having the ends of its extensions rigidlysecured to the downturned extensions 2 of the slide plate l, andprovided with a centrally upwardly bent portion 24, constitutes a handlefor maintaining my improved device in an upright position when in use.

I-Iaving fully described by invention, I claim:

l. In an ellipsograph, the combination of a suitably supported slideplate, having an elongated slot therein, a member mounted to slide insaid slot, swinging arms pivotally mounted at their outer ends adjacentthe ends of said slide plate, and provided with inner overlapping endshaving longitudinal slots,

a bolt engaging through said arm slots, to

move at right angles to said slide plate slot upon the swing' movementof said arms, an adjusting bar extending from the said slide member andlongi dinally slidably connected to said bolt, and a p '1 barlongitudinally slidably connected at one end tov said slide member inalinement with said adjusting bar, substantially as described.

2. In an ellipsograph, the combination of a suitably supported slideplate having an elongated slot therein, a member mo-unted to slide insaid slot, swinging arms pivotally mounted at their outer ends adjacentthe ends of said slide plate and provided with inner overlapping ends,having longitudinal slots, a bolt engaging through said arm slots, andslidable therein, means Jfor insuring uniform slidable movement of saidbolt within said slots, upon the swinging movement of said arms, anadjusting bar extending from the said slide member and longitudinallyslida bly connected to said bolt, and a pencil bar longitudinallyslidably connected at one end to said slide member in alinement withsaid adjusting bar, substantially as described.

In testimony whereof I atiX my signature in presence of two witnesses.

COLLIN P. BRICKEY. Witnesses:

H. C. LUMPKIN, EUGENE V. PLEss.

